Any Question Answered

[Crosland]

Here's a question regarding the use of Nigel Lawton's 6 volt motors. They are supplied with a 'dropper' resistor to drop 12 volts to 6 volts (presumably wired in series in one of the motor leads?).

 

Why then, has the Dapol pannier, which I now have in a hundred bits before me, have two resistors - one in each lead? Or do they have nothing to do with dropping the voltage?

 

David

(Electrically challenged)

 

Is it definitely a 6V motor with resistors? They could be inductors for interference suppression.

[Valentin]

The boiler diameter for the SER Class O (James Stirling's 1882 version) is 55". Translated into 2mm:1ft the diameter is approx. 9.15 mm. I cannot find a brass tube of this size but I've got a 9.5 mm tube. Will this difference be an obvious one on the model?

 

Thank you,

Edited February 4, 2017 by Valentin

[nick_bastable]

The boiler diameter for the SER Class O (James Stirling's 1882 version) is 55". Translated into 2mm:1ft the diameter is approx. 9.15 mm. I cannot find a brass tube of this size but I've got a 9.5 mm tube. Will this difference be an obvious one on the model?

 

Thank you,

use 9mm tube  its closer to scale  

 

NIck

[Gareth Collier]

My 'O' class is in N gauge but IIRC I went for a 9mm tube.

 

 

 

[Sam Kennion]

use 9mm tube  its closer to scale  

 

NIck

9mm plus paint will get you very close to 9.15mm.

 

Sam.

[Chris Higgs]

Not a question, but I couldn't help a smile at reading this on the Model Railway Club website.

 

"We are back at Alexandra Palace with a stand at the LMEE on 20-22nd January 2017. Our theme this year is "Electric Power", which includes a section of our new OO gauge model of Ingatestone which has 25kV overhead electricifcation."

 

I've heard of prototype fidelity but that's going a bit far.

Edited February 8, 2017 by Chris Higgs

[nick_bastable]

Not a question, but I couldn't help a smile at reading this on the Model Railway Club website.

 

"We are back at Alexandra Palace with a stand at the LMEE on 20-22nd January 2017. Our theme this year is "Electric Power", which includes a section of our new OO gauge model of Ingatestone which has 25kV overhead electricifcation."

 

I've heard of prototype fidelity but that's going a bit far.

but it would keep the poker's  and toucher away at exhibitions   

Nick

[Izzy]

Ah, that explains the problems with the overhead in that area recently then. The excuse as always was that it had been brought down again. Now we know it had instead been lent elsewhere.......

 

Izzy

[scanman]

Not a question, but I couldn't help a smile at reading this on the Model Railway Club website.

 

"We are back at Alexandra Palace with a stand at the LMEE on 20-22nd January 2017. Our theme this year is "Electric Power", which includes a section of our new OO gauge model of Ingatestone which has 25kV overhead electricifcation."

 

I've heard of prototype fidelity but that's going a bit far.

Reminds me of the layout which had BIG signs hanging from the front fascia - "DANGER - 12,000 MILLIVOLTS" !  Not much finger-poking there....

[Jim T]

Not a question, but I couldn't help a smile at reading this on the Model Railway Club website.

 

"We are back at Alexandra Palace with a stand at the LMEE on 20-22nd January 2017. Our theme this year is "Electric Power", which includes a section of our new OO gauge model of Ingatestone which has 25kV overhead electricifcation."

 

I've heard of prototype fidelity but that's going a bit far.

 

They've just forgotten to scale the voltage in the blurb - but I think it should scale with the cross sectional area of the conductor so it's actually 25,000 / (76.2 ^ 2) = 4.3 volts. Scary!

[oily]

Not sure where to put this or even if anyone might be interested but have a friend who is selling all his old 2mm stuff, he was about to bin most of it, but it includes:

Build an 0-6-0 in 2mm Scale. David Holland

An Introduction to Split Frame Chassis Design.

The Beginner’s Guide to 2mm Modelling.

The 2mm Handbook. 1990

Loco Bits and Pieces. Pete Wright.

Model Railways Bassett-Lowke Catalogue 1954 edition

Wheel Specifications for the Modeller. Mike Sharman

And he has some interesting old books on model railways like the old E F Carter Book on 000 Modelling, the Beal book on Modelling the Old Time Railways, books on model engineering, small lathes and so on. I even found an illustrated catalogue of Mr H B Whall's of Kew that must go back over 60 years.

If anyone is interested after I've had a pick!! contact me off this board with a message and I can put you in touch.

Oli

[2mmMark]

I heard E F Carter described as someone entirely unencumbered by any practical experience. 

 

That might be a touch unfair but I've got his 000 book and it's an interesting curio, recommending stud contact as a suitable system for 2mm.

 

Mark

[oily]

I've helped dismantle a layout and we have saved all the straight track and turnouts undamaged, some quite complex and some new and were never used. They're all soldered PCB so may not suit modern track builders, but they would save someone an awful lot of work.

I've made a list of turnouts and think they are mostly B7s but in addition to about 5 feet of straight track there are:

6 RH turnouts

3 LH turnouts.

4 crossovers, 2 leading and 2 trailing

2 LH turouts on a curve

A leading crossover running into a double slip.

We also uncovered a box of 2mm track building jigs, three triangular ones, and three roller gauges, two joined together for double track spacing and a host of other goodies, including plastic track bases and rail, old 2mm booklets, It goes on and on.

I don't understand the Buy & Sell section on here now, but if anyone is interested in any of it just email me or send me a message.

Regards

Oli

Edited February 12, 2017 by oily

[Nig H]

I've helped dismantle a layout and we have saved all the straight track and turnouts undamaged, some quite complex and some new and were never used. They're all soldered PCB so may not suit modern track builders, but they would save someone an awful lot of work.

I've made a list of turnouts and think they are mostly B7s but in addition to about 5 feet of straight track there are:

6 RH turnouts

3 LH turnouts.

4 crossovers, 2 leading and 2 trailing

2 LH turouts on a curve

A leading crossover running into a double slip.

We also uncovered a box of 2mm track building jigs, three triangular ones, and three roller gauges, two joined together for double track spacing and a host of other goodies, including plastic track bases and rail, old 2mm booklets, It goes on and on.

I don't understand the Buy & Sell section on here now, but if anyone is interested in any of it just email me or send me a message.

Regards

Oli

No-one understands the buy and sell on here anymore, it's incomprehensible.

 

Nig H

[Jim T]

No-one understands the buy and sell on here anymore, it's incomprehensible.

 

Nig H

 

It used to work so well back in the pre-BRM day as well. I tend to use the DEMU forum for modern image stuff, but is there a 2mm buy and sell lurking anywhere?

[Kylestrome]

......... is there a 2mm buy and sell lurking anywhere?

 

 

Members sales in the newsletter and probably also on the VAG.

 

David

[Valentin]

Hello,

 

 

I plan to build the model of a South Eastern Railway Class O (Stirling). For this I have already acquired the Worsley Works scratch-build aid kit. As the tender is quite small, I am thinking to follow one of Nick's ideas to put the motor in the boiler and the gear-train in the tender as illustrated below:

 

The gears on the wheel axles are 22 teeth (x 3), the spur gears are: two 18 teeth and one 14 teeth and the worm wheel is part of a 21:1 worm / wheel set. All the gears are M0.3. I would've liked to use a 30:1 or even a 38:1 gear-set but the worm wheel would have fouled one of the gear muffs.

 

Am I right in assuming the total reduction ratio is: 33:1 (22/18 x 18/14 x 21)? The plan is to use a cheap 716 motor (eBay), similar (or identical) to the new Graham Farish coreless motor. Using DCC, would be enough for shunting?

[Donw]

Hello,

 

 

I plan to build the model of a South Eastern Railway Class O (Stirling). For this I have already acquired the Worsley Works scratch-build aid kit. As the tender is quite small, I am thinking to follow one of Nick's ideas to put the motor in the boiler and the gear-train in the tender as illustrated below:

 

The gears on the wheel axles are 22 teeth (x 3), the spur gears are: two 18 teeth and one 14 teeth and the worm wheel is part of a 21:1 worm / wheel set. All the gears are M0.3. I would've liked to use a 30:1 or even a 38:1 gear-set but the worm wheel would have fouled one of the gear muffs.

 

Am I right in assuming the total reduction ratio is: 33:1 (22/18 x 18/14 x 21)? The plan is to use a cheap 716 motor (eBay), similar (or identical) to the new Graham Farish coreless motor. Using DCC, would be enough for shunting?

 

Not the usual way of doing things but the tender wheels should be smaller than the drivers so that will help for say 4ft tender wheels and 5ft drivers using the tender wheels  at 33:1 would be equivalent to 41:1 on the drivers.

Don

[Chris Higgs]

Hello,

 

 

I plan to build the model of a South Eastern Railway Class O (Stirling). For this I have already acquired the Worsley Works scratch-build aid kit. As the tender is quite small, I am thinking to follow one of Nick's ideas to put the motor in the boiler and the gear-train in the tender as illustrated below:

 

The gears on the wheel axles are 22 teeth (x 3), the spur gears are: two 18 teeth and one 14 teeth and the worm wheel is part of a 21:1 worm / wheel set. All the gears are M0.3. I would've liked to use a 30:1 or even a 38:1 gear-set but the worm wheel would have fouled one of the gear muffs.

 

Am I right in assuming the total reduction ratio is: 33:1 (22/18 x 18/14 x 21)? The plan is to use a cheap 716 motor (eBay), similar (or identical) to the new Graham Farish coreless motor. Using DCC, would be enough for shunting?

 

Those spur gears on the axles look awfully close to the diameter of the wheels. I am guessing 7.2mm for the gears, 7.5mm for the wheels?

 

Bear in mind with this design that the 18T idlers between the axles are going to be quite visible looking side-on.

 

The ratio is as you state, but the size of the 18T idler is irrelevant. Hence you could put in something larger, like a 20T which perhaps will allow you to use a 30:1 gearset. However, the drive shaft would then  be a fair bit higher.

 

Chris

Edited February 20, 2017 by Chris Higgs

[CF MRC]

I think that it's much nicer to see the loco wheels actually work for a living, rather than go along for the ride. The tender is easily big enough to take a small motor and it is possible to put much more weight into the engine than the tender, which can also then be weighted and load on to the back of the engine. The reverse of using the engine loading on to the tender may not work, because you may loose the ability of the loco to free wheel. Seems like an awful lot more work for no real gain and more gears to absorb energy and make a noise. The largest possible worm wheel on the centre driver with a simple worm mounting should give a controllable loco with modern controllers and motors.

 

Tim

[Caley Jim]

I fully agree with Tim. I can't see any logic in driving a tender from a motor in the loco. For a start you're going to have less adhesive weight and you're going to have to push aloco which will be less free running than a tender would be. The complication of getting all these gears running smoothly far outweighs any perceived complication from hearing the loco.

Jim

[Valentin]

Thank you all for your advice.

 

I was thinking to install the motor in the boiler / fire box, as low as possible then drive the rear axle via a 38:1 worm / wheel set.

 

The tender is wide enough, just not high enough for a 716 motor although only by 0.5 mm. I might have another look and lower the motor between the frames or putting a lump of coal...

 

Another question: how thin is too thin for the universal joint shaft? I used 0.010" guitar string and I don't think it works very well.

[Orange Cat]

A 7mm motor will fit within the back-to-back of 2mm FS wheelsets. The tender wheels are 3'9" on that loco, are they not? Used with the 2.3mm muffs that gives a height of 4.9mm to clear the muffs. Add your 7mm for the motor to that and you get 11.9mm. Add in a millimetre for clearance and unless the top of the tender is less than 6' 6" from the top of the rail there's loads of room for the motor.

[Caley Jim]

Another question: how thin is too thin for the universal joint shaft? I used 0.010" guitar string and I don't think it works very well.

That's what I use and have no problems.  You need to allow a little bit of end play for curves.  I have a c1.5mm deep slot in the end of the gear shaft on  the tender and the worm shaft on the loco with the end of each shaft flush with the outer face of the bearing.  Each end of the wire is bent into a tight loop c1mm in diameter and also squashed slightly.  The length is such that there is about 0.5mm end play in the drive shaft.

 

You can just see the slot in the end of the worm shaft in this photo of the chassis of my 0-4-2.

 

In this case the worm is below the wormwheel.  This enabled me to keep the drive below footplate level and so out of sight on a loco which has a very open cab.  It is the arrangement I have on all three of my tender locos.  The loco is beam compensated BTW.

 

Jim

[Chris Higgs]

A 7mm motor will fit within the back-to-back of 2mm FS wheelsets. The tender wheels are 3'9" on that loco, are they not? Used with the 2.3mm muffs that gives a height of 4.9mm to clear the muffs. Add your 7mm for the motor to that and you get 11.9mm. Add in a millimetre for clearance and unless the top of the tender is less than 6' 6" from the top of the rail there's loads of room for the motor.

 

7mm motors can fit entirely between the wheels, and even 8mm one can be dropped pretty low down. This can prove very advantageous in many cases.

 

Chris